Handling of objects being speech+noise

Outcoem from F2F meetin discussion (https://forge.3gpp.org/rep/ivas-codec-pc/ivas-codec/-/wikis/Meetings/Reports/2023-02-27-03-01%20F2F%20Meeting/2023-02-27-03-01%20F2F%20Meeting%20Agenda):

Handling of Speech + Noise

• Up to which level should backgrounds considered?
• Reported problems on segments with strong, static background noise, where VAD = 0, which impacts reproduction of background noise; observed problems with change in level when going from active to inactive
• Nokia considers that objects might be noisy, too; however, in practice probably most objects are rather clean; can't really control this input
• --> @vaclav to check behavior

Consequently, a tuning of when the low-rate coding mode in ISM is triggered is needed.